Sirius
Sirius Union Star System – Binary Star System – Belonging to the Saran Empire. Known also as Irtyu (Saran for “Blue”). Major Saran Star System and the closest Saran System to Earth. ---- The System has five planets and is surrounded by a large Matter and Dust Cloud called Sirius Veil(it periodically obscures the Star and makes it appear red instead of blue (to Earth Observers) The Dust Cloud is minded and scooped since Sirius is a Union System. ---- Star Details 'α CMa A' *Mass 2.027 M☉ *Radius 1.7117 R☉ *Luminosity 25.47 L☉ *Surface gravity (log g) 4.338 *Temperature 9,9408 K *Metallicity Fe/H 0.509 dex *Rotation 16 km/s10 *Age 2–3 × 1087 years 'α CMa B ' *Mass 0.9787 M☉ *Radius 0.0084 ± 3%11 R☉ *Luminosity 0.0263 L☉ *Surface gravity (log g) 8.5711 *Temperature 25,2007 K The Planets * *Tefer *Khesbedj *Lapis lazuli *Metopasi *Haktu General Info Sirius is the brightest star in the night sky. With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star. The name "Sirius" is derived from the Ancient Greek: Σείριος Seirios ("glowing" or "scorcher"). The star has the Bayer designation Alpha Canis Majoris (α CMa). What the naked eye perceives as a single star is actually a binary star system, consisting of a white main-sequence star of spectral type A1V, termed Sirius A, and a faint white dwarf companion of spectral type DA2, called Sirius B. The distance separating Sirius A from its companion varies between 8.1 and 31.5 AU.18 Sirius appears bright because of both its intrinsic luminosity and its proximity to Earth. At a distance of 2.6 parsecs (8.6 ly), as determined by the Hipparcos astrometry satellite,51920 the Sirius system is one of Earth's near neighbors; for Northern-hemisphere observers between 30 degrees and 73 degrees of latitude (including almost all of Europe and North America), it is the closest star (after the Sun) that can be seen with a naked eye. Sirius is gradually moving closer to the Solar System, so it will slightly increase in brightness over the next 60,000 years. After that time its distance will begin to recede, but it will continue to be the brightest star in the Earth's sky for the next 210,000 years.21 Sirius A is about twice as massive as the Sun and has an absolute visual magnitude of 1.42. It is 25 times more luminous than the Sun7 but has a significantly lower luminosity than other bright stars such as Canopus or Rigel. The system is between 200 and 300 million years old.7 It was originally composed of two bright bluish stars. The more massive of these, Sirius B, consumed its resources and became a red giant before shedding its outer layers and collapsing into its current state as a white dwarf around 120 million years ago.7 Sirius is also known colloquially as the "Dog Star", reflecting its prominence in its constellation, Canis Major (Greater Dog).12 The heliacal rising of Sirius marked the flooding of the Nile in Ancient Egypt and the "dog days" of summer for the ancient Greeks, while to the Polynesians it marked winter and was an important star for navigation around the Pacific Ocean. Sirius, known in ancient Egypt as Sopdet (Greek: Σῶθις = Sothis), is recorded in the earliest astronomical records. During the era of the Middle Kingdom, Egyptians based their calendar on the heliacal rising of Sirius, namely the day it becomes visible just before sunrise after moving far enough away from the glare of the Sun. This occurred just before the annual flooding of the Nile and the summer solstice,22 after a 70-day absence from the skies.23 The hieroglyph for Sothis features a star and a triangle. Sothis was identified with the great goddess Isis, who formed a part of a triad with her husband Osiris and their son Horus, while the 70-day period symbolised the passing of Isis and Osiris through the duat (Egyptian underworld).23 The ancient Greeks observed that the appearance of Sirius heralded the hot and dry summer, and feared that it caused plants to wilt, men to weaken, and women to become aroused.24 Due to its brightness, Sirius would have been noted to twinkle more in the unsettled weather conditions of early summer. To Greek observers, this signified certain emanations which caused its malignant influence. Anyone suffering its effects was said to be astroboletos (ἀστροβόλητος) or "star-struck". It was described as "burning" or "flaming" in literature.25 The season following the star's appearance came to be known as the Dog Days of summer.26 The inhabitants of the island of Ceos in the Aegean Sea would offer sacrifices to Sirius and Zeus to bring cooling breezes, and would await the reappearance of the star in summer. If it rose clear, it would portend good fortune; if it was misty or faint then it foretold (or emanated) pestilence. Coins retrieved from the island from the 3rd century BC feature dogs or stars with emanating rays, highlighting Sirius' importance.25 The Romans celebrated the heliacal setting of Sirius around April 25, sacrificing a dog, along with incense, wine, and a sheep, to the goddess Robigo so that the star's emanations would not cause wheat rust on wheat crops that year.27 Ptolemy of Alexandria mapped the stars in Books VII and VIII of his Almagest, in which he used Sirius as the location for the globe's central meridian. He curiously depicted it as one of six red-coloured stars (see the Red controversy section below). The other five are class M and K stars, such as Arcturus and Betelgeuse.28 Dogon See also: Nommo The Dogon people are an ethnic group in Mali, West Africa, reported to have traditional astronomical knowledge about Sirius that would normally be considered impossible without the use of telescopes. According to Marcel Griaule's books Conversations with Ogotemmêli and The Pale Fox they knew about the fifty-year orbital period of Sirius and its companion prior to western astronomers. They also refer to a third star accompanying Sirius A and B. Robert Temple's 1976 book The Sirius Mystery, credits them with knowledge of the four Galilean moons of Jupiter and the rings of Saturn. This has been the subject of controversy and speculation. According to a 1978 Skeptical Inquirer article it is possibly the result of cultural contamination.114 Some have suggested the contaminators to have been the ethnographers themselves.115116 Others see this explanation as being too simplistic.117 Yoonir, symbol of the Universe in Serer religion.118119edit Serer religionMain articles: Serer religion and Saltigue In the religion of the Serer people of Senegal, the Gambia and Mauritania, Sirius is called Yoonir from the Serer language (and some of the Cangin language speakers, who are all ethnically Serers). The star Sirius is one of the most important and sacred stars in Serer religious cosmology and symbolism. The Serer high priests and priestesses, (Saltigues, the hereditary "rain priests"120) chart Yoonir in order to forecast rain fall and enable Serer farmers to start planting seeds. In Serer religious cosmology, it is the symbol of the universe.118119 Sirius A An artist's impression of Sirius A and Sirius B. Sirius A is the larger of the two stars.Sirius A has a mass double that of the Sun.778 The radius of this star has been measured by an astronomical interferometer, giving an estimated angular diameter of 5.936±0.016 mas. The projected rotational velocity is a relatively low 16 km/s,10 which does not produce any significant flattening of its disk.79 This is at marked variance with the similar-sized Vega, which rotates at a much faster 274 km/s and bulges prominently around its equator.80 A weak magnetic field has been detected on the surface of Sirius A.81 Stellar models suggest that the star formed during the collapsing of a molecular cloud, and that after 10 million years, its internal energy generation was derived entirely from nuclear reactions. The core became convective and utilized the CNO cycle for energy generation.79 It is predicted that Sirius A will have completely exhausted the store of hydrogen at its core within a billion (109) years of its formation. At this point it will pass through a red giant stage, then settle down to become a white dwarf. Sirius A is classed as an Am star because the spectrum shows deep metallic absorption lines,82 indicating an enhancement in elements heavier than helium, such as iron.7379 When compared to the Sun, the proportion of iron in the atmosphere of Sirius A relative to hydrogen is given by ,9 which is equivalent to 100.5, meaning it has 316% of the proportion of iron in the Sun's atmosphere. The high surface content of metallic elements is unlikely to be true of the entire star, rather the iron-peak and heavy metals are radiatively levitated towards the surface.79 Sirius B The orbit of Sirius B around A as seen from Earth (slanted ellipse) and as seen face-on (wide horizontal ellipse).With a mass nearly equal to the Sun's, Sirius B is one of the more massive white dwarfs known (0.98 solar masses83); it is almost double the 0.5–0.6 solar-mass average. Yet that same mass is packed into a volume roughly equal to the Earth's.83 The current surface temperature is 25,200 K.7 However, since there is no internal heat source, Sirius B will steadily cool as the remaining heat is radiated into space over a period of more than two billion years.84 A white dwarf forms only after the star has evolved from the main sequence and then passed through a red giant stage. This occurred when Sirius B was less than half its current age, around 120 million years ago. The original star had an estimated 5 solar masses7 and was a B-type star (roughly B4-5)8586 when it still was on the main sequence. While it passed through the red giant stage, Sirius B may have enriched the metallicity of its companion. This star is primarily composed of a carbon–oxygen mixture that was generated by helium fusion in the progenitor star.7 This is overlaid by an envelope of lighter elements, with the materials segregated by mass because of the high surface gravity.87 Hence the outer atmosphere of Sirius B is now almost pure hydrogen—the element with the lowest mass—and no other elements are seen in this star's spectrum.88 Category:Solar Systems